Packaging ebay stuff

[KateMateDateFateLateBateGate]

I have to post a coat to the successful ebay bidder. How to I best package it? Do I have to buy address labels or just stick a iece of are with the address on the parcel?

I use plastic mail bags and write on them with a sharpie

Yabu

As long as the package is secure (coat won't fall out or get damaged or dirty en route), and the destination address is clear (and won't fall off), and the postage is paid, then I think it is up to you how to package it.
Presumably you are selling as a private individual; so no need to present an overly-professional image; equally you don't want to invite negative ratings.
Consider how you would feel receiving the parcel - would you think it well packaged and secure?

acquiescence -

I would put it in a box, actually. Never seems to make a difference to the price of courier & the label can be secure; labels fall off of plastic bags very easily. Plastic bags as wrapping can be punctured & the contents damaged or the whole thing shredded. Maybe not if the weight is going to go too high, but I always try to put things in cardbox boxes if I can.

ps: sharpie can rub off. Trust me, I've had everything else go wrong!

Keep the parcel under 25mm thick if possible, it's a lot cheaper to post that watt

"Yabu"

Thanks to everyone else